A volcano named Sapas Mons dominates this computer-generated view of the surface of Venus. Lava flows extend for hundreds of kilometers across the fractured plains shown in the foreground to the base of the mountain, which measures 248 miles (400 km) across and 0.9 mile (1.4 km) high.

It’s got to be frustrating for planetary scientists that the world closest to Earth and most similar in size as well—so similar that it’s often described as our planet’s twin—is in many ways the toughest to study. Venus’ perpetual shroud of thick, opaque clouds makes it impossible to see the surface with even the most powerful telescopes, and its sweltering surface temperature (think 900°F) makes it impossible for landers to survive for more than a few minutes.

Nevertheless, orbiting spacecraft armed with radar and other instruments have taught scientists quite a lot about Venus’ atmosphere over the years, and even its surface—and a new study in Nature Geoscience is now reporting another, intriguing piece of information. The European Space Agency’s Venus Express has detected a sharp decline in sulfur dioxide (SO2) concentrations in the planet’s atmosphere following a spike in SO2 just after the probe arrived in 2006. The most plausible explanation, says lead author Emmanuel Marcq, is a volcanic eruption, caught in the act.

It’s not the only possible explanation, he admits. “We know that on Earth there are long-term atmospheric cycles, so it could happen on Venus as well. We can’t dismiss this possibility at the moment.”

Volcanoes, however, are a lot more likely. One reason is that they’re known sources of SO2, at least on Earth. Another is that Venus is peppered with them — hundreds upon hundreds of volcanic mountains, lava flows and other features that make the planet’s history of volcanism unmistakable. Most of them appear to be long dead, but there have been hints in the past that a few might still be active. In the early 1990’s for example, radar on the Magellan spacecraft detected what appeared to be fresh lava, and back in the early 1980’s Pioneer Venus documented SO2 levels nearly 50 times higher than anyone expected, followed by a steady dramatic decline. “It’s very similar,” he says, “to the one we’re observing now.”

If a volcano really did erupt just after Venus Express showed up, the event could have been seen directly by the satellite’s infrared detectors — but only on the planet’s night side, since average daytime temperatures are so high that an extra hotspot wouldn’t stand out very easily. And even so, the orbiter only passes over a given spot on the Venusian surface every 100 days. “It’s unlikely,” says Marcq, “that we would be able catch an eruption.”

It’s also highly unlikely that this eruption, or any conceivable eruption on Venus, could do much to make the planet more hospitable. When a big volcano goes off on Earth — Krakatoa, for example, or even the more modest Pinatubo — its sulfur dioxide output forms light-reflecting particles high in the stratosphere that bounce sunlight back into space and temporarily cool the planet. Indeed, volcanic eruptions are one of the natural forces that climate scientists take into account when trying to discern the fingerprint of manmade climate change.

On Venus, however, the carbon-dioxide-rich atmosphere has created a runaway greenhouse effect and global warming beyond anyone’s worst nightmares. This recent eruption could cool the planet – but only by a few degrees. When you’re talking temperatures that are already hot enough to melt lead, a few degrees of relief isn’t going to make a whole lot of difference for vulnerable rovers – or astronauts.

I really believe we are limited by our own biology. We keep insisting that water is essential for life. We only believe this because we are yet to discover otherwise. So until we do, we wre limited in our searching.

PS - we are all originally from Mars. We destroyed that planet and moved on to earth.....but I have no proof...

It's time for genetic engineers to see what they can do as terraformers. They could try to adapt organisms, like those heat resistant ones found near volcanic vents, into neutralizing Venus's atmospheric acid. Getting rid of those acidic clouds seems like the first step to me. Machinery won't do it, so biology must. Engineered for rapid generations, such an organism could show a planet-wide effect in mere decades.

I agree jaareshiah, Earth is unique. One in a million IS unique, but our galaxy alone contains trillions upon trillions of stars with countless planets orbiting them. This makes Earth, and millions of other planets, unique but not alone by any means. It would appear your God(s) has been very busy "designing". Me thinkst thou dost anthropomorphize too much.

This proves a point, that the earth is unique in the universe, able to not only sustain life, but make it enjoyable. The earth was not an accident in the cosmos, but an intentional creation of a Master Designer. Within the Bible is found his name, Jehovah.(Ps 83:18) He purposefully made the earth full of life, of such variety as to stagger the imagination.(Ps 104:24, 25)

He precisely placed the earth within our Milky Way galaxy, with our solar system some 28,000 light years from the center, and being called the galactic hospitable zone by many scientists, where it is just the right concentration of chemical elements needed to support life. And within our solar system, he exactly placed the earth just right distance from the sun, being called the circumstellar habitable zone, where life neither freezes nor fries.

Venus, on the other hand, fries anything placed on it, with 900 degrees F. and of Mars, it may have some water, but it remains frozen on the Martian poles, with temperatures dropping as low as -225 degrees F. at the poles. Thus, the earth is not only the right distance from the sun, but also the right size, for if it were slightly smaller, with a weaker gravitational field, life sustaining oxygen and surface water would escape, and eventually our planet would be barren from the loss of all water. If it were larger, it would have a slightly stronger gravitational field and therefore hydrogen, a light gas, could not escape into space, building up and eventually rendering our planet inhospitable.

@EzMarcPoschman Yes. The problem with terraforming Venus is the same as with Mars: No global magnetosphere remains which results in all sorts of problems for possible human colonists, but it's certainly not beyond our likely future capabilities to genetically engineer flora and perhaps fauna that could survive on a future terraformed Venus, even if humans themselves could never stand on it's surface without extra gear.

@IceT Listen, Ice... - When you get back to Asgard this evening, sneak in word to Hemidall to leave the back door open a crack tonight ( I got a hot date) and I'll bring him back the new Chris Brown CD he's been dying for.

What makes earth unique? The fact that our planet has dihydrogen oxide, carbon, and is in fact the right distance from the sun - a G-star. Those are the basic ingredients for life to exist. I've studied astrobiology in college. Sure, discoveries of planets made of solid carbon (diamond) are wonderful, but unless they have water and reasonable distance from a star to harbor life, then the possibility of colonization is slim. I accept Giordano Bruno's theory of life in the universe, and NASA is getting closer to proving it. I do feel it will happen during my lifetime. At this point in human history on this little rocky planet, discovering other habitable planets is more important than ever before.

@jaareshiah What an utter load of crapola. The old testament is a colection of works by many ancient people who had no idea of the universe, beyond what they say in the sky. It is NOT the revealed wisdom of a diety with origins in Egypt and Mesopotania.

Further, unless you have personally conducted a survey of the galazy and have detailed information on each planet, you cannot say that the earth is unique.

You are ignorant my friend. Pick up a book that was written in the past 100 50 years, not only written thousands of years ago and corrupted by the passage of time.

In defense of Mars, there is water to be had as well in the form of planetary snowstorms. (some of these, it is true, are Co2 snowstorms) At one time too Mars had vast oceans and a richer atmosphere. Yet even as it is today, amazing photographs of the Martian landscape allow the viewer to imagine walking through those stark but somehow familiar looking landscapes.

@jaareshiah I know you want to believe some invisible man created everything around us because it's just too hard to understand in your one track mind, but people that don't give up so easily on life have already figured out how Earth was created. If you feel like learning something, check this website out. http://en.wikipedia.org/wiki/Universe

@JangoDavis@jaareshiah We know you deparately want to be free of God's judgment and his laws (doesnt fit your lifestyle huh?), but next time try to research some evidence against the Bible. It is scientifically, and historically, infallible. See the dead sea scrolls found in 1947. Take care. Oh and some research into the unchanging laws of physics and the gravitational force on earth wouldnt hurt you either.

@Rando I can't believe the amount of religious people are in the science section of Time and refuse to admit they're wrong and dismiss everything that is scientifically PROVEN. There's literally no hope for America lately. Good thing religion is dying off in Europe. There just might be hope for the rest of the world.

@Rando I know you want to believe the big bang theory and primordial soup theories as 'science', but the truth is these theories couldnt be futher from being observed (billions of years ago). Only 'science' should be in 'science books', but this isnt what we see today. The atheists still make all other americans pay for their religion to be taught in public schools as fact. Have a nice day.

@Rando - these are the same scientist that cant even cure the common cold and they have solve the mystery of the Universe. I am not anti science, but get real Rando in making a statement that they have figured out how the earth was created.

@IceT Actually wikipedia is very heavily edited, I once went to an obscure article on there (3PV or Third Party Verification) and added to it that it was created by aliens as a way for them to break into the boy band market and it was removed in 10 minutes. It's even accepted by quite a few universities as a reliable source now. And yes, our galaxy does supposedly contain about 200 billion stars. Here's a non-wiki link http://moonphases.info/number-of-stars-in-the-milky-way.html

@RaimoKangasniemi@vjsd11 Wrong again, look up Job. See how far back any other religious manuscripts date while youre at it. People say the vedas is old but the oldest surving manuscripts (made from papyrus and palm leaves) only date back to the 11th century. Its basically one of the oldest stories known to man along with gilgamesh.

@vjsd11 Book of Job was compiled between 600-300 BCE, probably closer to 300 BCE. There are Egyptian and Mesopotamian stories of similar nature and it might represent a particular genre in Middle Eastern literature of the time, but the actual Book of Job is just about 2500 years old.

None of the Dead Sea Scrolls date beyond 400 BCE as none of them date even beyond 200 BCE. Almost all of them date to 1st century BCE or early 1st CE. Few of the writing materials might come from 2nd century BCE, the text might be younger.

@RaimoKangasniemi@vjsd11@JangoDavis@jaareshiah Actually the book of Job was written about 2,000 BC, thats not the point. The actual saved manuscript is. There are hundreds of scrolls, not all written at the same time. Im sure you have credible sources for your carbon dating of 100 bc - 50 bc (even though carbon dating gives widely ranging dates). Other sources will tell you the scrolls date beyond 400 bc. Good luck to you.

Well, phyicist Stephen Hawking has stated that we may define God generically as the source of the laws of physics. While this is not the same as espousing a particular religious dogma it nevertheless makes clear that the physical universe, as the result of a first cause, (God) cannot be fully understood apart from it.